Improve Bufwaits Ratio

Hi, What Bufwaits Ration and Buffer Turnover Rate mean? How can the improved? Thanks SZ Disclaimer This message may contain privileged - confidential information and is intended exclusively to the addressees (or any person in charge to deliver to the addresses) . If you are not the intended recipient, you may not use, copy, distribute or deliver this message (or part of its contents) to anyone or take any action in reliance on it. In such a case, you should destroy this message, and notify the sender. All reasonable precautions have been taken to ensure no viruses are present in this e-mail. However, as Internet is a non secure environment; we will bear no responsibility for any loss or damage arising from the use of this e-mail or attachments. Thus, we recommend that you subject these to your virus checking procedures prior to use. If any investment information is contained herein, it has been provided to you for informational purposes only and may not be relied upon in the process of evaluating the merits of investing in any financial instruments referred to herein. It is not a research report, a trade confirmation or an offer or solicitation of an offer to buy/ sell any financial instruments Views, opinions, conclusions and other information expressed in this e-mail are not given or endorsed by Marfin Egnatia Bank S.A. Group of Companies unless otherwise indicated by an authorized representative independent of this message. Ãíùóôïðïßçóç/ Áðïðïßçóç Åõèýíçò Tï ðáñüí ìÞíõìá åíäÝ÷åôáé íá ðåñéëáìâÜíåé åìðéóôåõôéêÝò – áðüññçôåò ðëçñïöïñßåò êáé áðåõèýíåôáé áðïêëåéóôéêÜ óôïõò óêïðïýìåíïõò ðáñáëÞðôåò (Þ õðåýèõíï ãéá ôçí ðáñÜäïóÞ ôïõ óôïõò áíôßóôïé÷ïõò óêïðïýìåíïõò ðáñáëÞðôåò). Óå ðåñßðôùóç ðïõ ðåñéÝëèåé óå åóÜò áðü ëÜèïò, äåí èá ðñÝðåé íá ÷ñçóéìïðïéÞóåôå, áíôéãñÜøåôå, äéáíåßìåôå Þ ðáñáäþóåôå óå ïðïéïíäÞðïôå ôï ðáñüí ìÞíõìá (Þ ôìÞìá ôïõ ðåñéå÷ïìÝíïõ ôïõ), ïýôå íá ðñïâåßôå óå ïðïéáäÞðïôå åíÝñãåéá âÜóåé áõôïý. Óôçí ðåñßðôùóç áõôÞ èá ðñÝðåé íá êáôáóôñÝøåôå ôï ðáñüí ìÞíõìá êáé íá åéäïðïéÞóåôå ôïí áðïóôïëÝá. ¸÷ïõí ëçöèåß üëá ôá åýëïãá ìÝôñá áóöáëåßáò ðñïêåéìÝíïõ ôï ðáñüí ìÞíõìá íá ìçí ðåñéëáìâÜíåé éïýò. ÄåäïìÝíïõ üôé ç åðéêïéíùíßá ìÝóù äéáäéêôýïõ (Internet) äåí åßíáé áóöáëÞò, äåí áðïäå÷üìáóôå ôçí åõèýíç ãéá ïðïéáäÞðïôå æçìßá Þ áðþëåéá ðñïêýøåé áðü ôç ÷ñÞóç ôïõ ðáñüíôïò Þ ôùí óõíçììÝíùí ôïõ êáé óõíéóôïýìå íá ôï õðïâÜëåôå óôéò äéáäéêáóßåò ðñüëçøçò éþí ðïõ äéáèÝôåôå ðñéí ôç ÷ñÞóç áõôïý. Áí ôï ðáñüí ðåñéëáìâÜíåé ðëçñïöïñßá åðåíäõôéêïý ðåñéå÷ïìÝíïõ, áõôÞ ðáñÝ÷åôáé áðïêëåéóôéêÜ ãéá åíçìåñùôéêïýò óêïðïýò êáé äåí èá ðñÝðåé íá âáóéóôåßôå óå áõôÞ êáôÜ ôçí áîéïëüãçóç ôçò óêïðéìüôçôáò ôçò åðÝíäõóçò óå ïðïéáäÞðïôå áðü ôá ÷ñçìáôïïéêïíïìéêÜ ðñïúüíôá ðïõ ôõ÷üí áíáöÝñïíôáé. Ôï ðáñüí äåí áðïôåëåß áíÜëõóç, åðéâåâáßùóç óõíáëëáãÞò Þ ðñïóöïñÜ Þ ðñïþèçóç ðñïóöïñÜò ãéá áãïñÜ/ ðþëçóç ïðïéùíäÞðïôå ÷ñçìáôïïéêïíïìéêþí ðñïúüíôùí. Ïé áðüøåéò, ãíþìåò, óõìðåñÜóìáôá êáé Üëëåò ðëçñïöïñßåò ðïõ ðåñéëáìâÜíïíôáé óôï ðáñüí ìÞíõìá çëåêôñïíéêïý ôá÷õäñïìåßïõ äåí äßäïíôáé ïýôå Ý÷ïõí åãêñéèåß áðü ôéò åôáéñåßåò ôïõ Ïìßëïõ Marfin Åãíáôßá ÔñÜðåæá Á.Å., åêôüò åÜí äçëùèåß ôï áíôßèåôï áðü åîïõóéïäïôçìÝíï åêðñüóùðü ôïõ áíåîáñôÞôùò ôïõ ðáñüíôïò.

BR or Bufwaits Ratio is the ratio of bufwaits to IO operations that require the engine to write to a buffer. The formula is: BR = ((bufwaits / (dskreads + bufwrites)) * 100.0 Values for BR <= 7.0 are ideal, values between 7.1 and 10.00 indicate a server that may be getting slow, and values of 10.00 and above are death - the server is running VERY slowly and likely you are getting complaints from users. BTR or Buffer Turnover Rate is a representation of the rate at which the buffer pool is being turned over - ie an estimate of how often the entire bufferpool is replaced. The formula is: BTR = ((BUFFERS / (dskreads + bufwrites)) / <stat age>) where <stat age> is the fractional hours since the stats were last zerod out (ie startup or when onstat -z was run after startup). You can find this time in seconds in the sysmaster.sysshmvals table. The field sh_pfclrtime is the epoch when stats were last cleared and sh_curtime is the current epoch, so sh_curtime - sh_pfclrtime is the number of seconds since stats were cleared. Divide by 3600.00 without truncating the fraction to get the <stat age> value. Values less than 10.00 are usually fine, higher values may indicate that the buffer cache is too small. If you using IDS 10.00 or later and multiple buffer pools, calculate both of these metrics independently for each pool for most accurate results. Tuning: High BTR - check onstat -P if there is a significant value (ie > 100) in the 'other' column for partnum zero (first line of the report), likely the buffer pool is big enough and something else is going on. Otherwise watch onstat -P over time and see if there are a small number of partnums that are thrashing a subset of the buffer pool between them. If so, increase BUFFERS by the number of buffers that seems to be traded back and forth -or go through the exercise to determine you actual data working set size and resize the buffer pool accordingly. High BR - Thei amy also mean the buffer pool is too small, so check that. Most often it means that you do not have enough LRU queues to prevent contention for clean buffers to overwrite. Increase LRUS or the lru field to the BUFFERPOOL parameter. If possible make sure you have one LRU for no more than 100 users, but that's only a guideline. Art 2008/6/26 Sergios Zagotsis <szagotsis@marfinbank.gr>: > Hi, > > What Bufwaits Ration and Buffer Turnover Rate mean? > > How can the improved? > > Thanks > > SZ > > Disclaimer > > This message may contain privileged - confidential information and is > intended > exclusively to the addressees (or any person in charge to deliver to the > addresses) . If you are not the intended recipient, you may not use, copy, > distribute or deliver this message (or part of its contents) to anyone or > take > any action in reliance on it. In such a case, you should destroy this > message, > and notify the sender. > > All reasonable precautions have been taken to ensure no viruses are present > in > this e-mail. However, as Internet is a non secure environment; we will bear > no > responsibility for any loss or damage arising from the use of this e-mail > or > attachments. Thus, we recommend that you subject these to your virus > checking > procedures prior to use. > > If any investment information is contained herein, it has been provided to > you > for informational purposes only and may not be relied upon in the process > of > evaluating the merits of investing in any financial instruments referred to > herein. It is not a research report, a trade confirmation or an offer or > solicitation of an offer to buy/ sell any financial instruments > > Views, opinions, conclusions and other information expressed in this e-mail > are not given or endorsed by Marfin Egnatia Bank S.A. Group of Companies > unless otherwise indicated by an authorized representative independent of > this > message. > > / > > T > ( > ). > > , > , > , ( > > ), > . > > . > > > > . (Internet) > > , > > > . > > , > > > > > . > , / > . > > , , > > > Marfin .., > . > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves.